When these things were discovered, we wondered if other planets had magnets in them and had plasma doing the same things as earth. We certainly cannot see their aurora with a telescope because it would be too small and dim. When we sent the space robots Pioneer and Voyager to Jupiter and Saturn, this is one of the questions we wanted to answer.

When Voyager got close to Jupiter, it sent back radio that sounded like this....

Jupiter's Audio from Voyager I

This signal told us that Jupiter was a magnet with plasma acting very much as it does on earth.